The polyprotic acids have more than one dissociation constant called K. For diprotic acids having K1 and K2 close enough, it is not possible to differentiate between two stages of neutralization while titrating. All the replaceable H+ ions tend to titrate in the single stage and the value of K2 becomes very low. So when it is titrated, the sharp change in pH occures near the 1st equivalent point. But the pH range in this point will be 4-6 i.e. acidic in nature. When phenolphthalein is used as the indicator, there will be no change in color, as the pH range of Phenolphthalein is 8-10. The 2nd equivalent point will be near the range of 8-10 and the color of Phenolphthalein will change from colorless to light pink in that range. But it will be unable to show the two different equivalent point separately. So it is not possible to tell if the acid is monoprotic or polyprotic. Similarly, when titrating the Tri or Tetraprotic acids or so on, the same problem will occur. Thus, Phenolphthalein is not a good choice as the indicator in this type of thing titration.
In a titration (one that doesnt measure pH), is it possible to tell if an acid...
A titration of 25.00 mL of an acetic acid solution with 0.1220 M NaOH solution starts at a burette reading for NaOH of 0.17 mL. The phenolphthalein indicator turns light pink in the acid solution for over 30 seconds at a burette reading of 36.32 mL. The volume of NaOH used to neutralize the acid is _______ mL.
QUESTION 1 6 points Save Answer The purpose of an indicator in an acid-base titration is to indicate the of the titration. Use Table 10.2 for the following question. If an acidic solution is titrated with a basic solution and methyl violet is used as an indicator, the solution color will change from to QUESTION 2 3 points Save Answer The molarity of a solution prepared by dissolving 17.0 g of hydrochloric acid (HCI (aq) in 133 mL of water...
Colours of phenolphthalein indicator 100 Alkaline End-point True False 1. The phenolphthalein indicator is not affected by the pH of the solution. 2. The phenolphthalein Indicator changes colour close to the point of neutralisation which shows the end-point of the titration, 3. When adding acid to base the phenolphthalein indicator changes colour from colourless to pink at the end of the titration Titra Acids and alkalis
Show all work and steps please 24 Phenolphthalein is a commonly used indicator that is colorless in the acidic form (pH less than 8 3) and pink in the base form (pH greater than 100) It is a weak acid with a pka of 8.7. What fraction is in the acid form when the ocid color is apparent? What fraction is in the base form when the base color is apparent? 24 Phenolphthalein is a commonly used indicator that is...
It's a weak acid strong base titration Experiment 4: Identification of an unknown acid by titration Page 2 of 15 Background In this experiment, you will use both qualitative and quantitative properties to determine an unknown acid's identity and concentration. To do this analysis, you will perform a titration of your unknown acid sample-specifically a potentiometric titration where you use a pH meter and record pH values during the titration, combined with a visual titration using a color indi- cator...
The following graph shows the pH curve for the titration of 25 mL of a 0.1 M monoprotic acid solution with a 0.1 M solution of a monoprotic base. mL of 0.1 M base added (1) The pH curve represents the titration of a _______(weak/strong) acid with a _______(weak/strong)base. (2) Choose a suitable indicator for the endpoint of the titration from the following pulldown list __________.(bromocresol green / methyl red / bromothymol blue / cresol red / thymol blue /...
Why is it important to get as light as a ping as possible for acid be titrations (when using phenolphthalein as an indicator)
A titration of 25.00 mL of O.1550 M HCl solution with a solution of NaOH of unknown molarity starts at a buret reading for NaOH of 0.33 mL The phenolphthalein indicator turns light pink the acid solution for over 30 seconds at a buret reading of 24.19 mL 2) What was the volume of HCl you started with? 3) How many moles of HCl were in the original solution? 4) Write the balanced chemical equation for the titration reaction. 5)...
Titration Curves of Polyprotic Acids 7. Derive the relationship between pH and på, at one-half the equivalence point for the titration of a weak acid with a strong base 8. Could K, for a weak base be determined the same way that K, for a weak acid is determined in this experiment? 9. What is the relationship of the successivo equivalence point volumes in the titration of a polyprotic acid? 10. If the pk of a diprotic acid is 2.90,...
Experiment 6. Acid-Base Titration Name Person # Teaching Assistant Darc Section Code Data Sheet * Unknown is a Diprotic Acid Table 6.1. Mass and volume data for titration of primary standard acid and unknown acid with sodium hydroxide. M -1 Trial 1 T rial Trial 3 Mass of weighing paper (g) 0,3898 10.3794 0.4041 Mass of weighing paper and oxalic acid, H,C,0,2H,0 (g) 0.5828 10.5634 0.5947 Initial reading of buret (mL) 2.59 0.00 oslo Final reading of buret (mL) 24....